Date: May 7, 2013 6:31 PM
Author: fom
Subject: Re: Collinear

On 5/7/2013 5:25 PM, fom wrote:
> On 5/7/2013 2:48 AM, William Elliot wrote:
>> Let C be a collection of n points with the property that
>> any line L with two points of C on it, has a third point
>> of C on it.
>>
>> How is it that C is collinear, ie all points of C are
>> on a single line?
>>

>
>
> Is this true?
>
> If I recall, there is something from
> design theory called a Pasch configuration.
>
>
> ABC
> AEF
> BDF
> CDE
>
>
> C
> |
> B
> |
> | D
> |
> A----E---F
>
> Maybe I am not recalling correctly.
>
> This is better:
>
> http://mathworld.wolfram.com/PaschConfiguration.html
>
>


Whoops!

Obviously was not thinking....